Order from chaos? 1/f noise predicts performance on reaction time measures

In repetitive tasks, latencies typically display non-random variation called 1/f noise, but the magnitude of 1/f noise can depend on effort. Between-participant variation in 1/f noise might therefore predict differences in performance for tasks that are sensitive to effort. Feedback was manipulated to suggest that participants had (or had not) shown bias on a preliminary task. Participants then completed a computer-based measure of prejudice. Consistent with an ironic process account, participants who were falsely informed that they had shown bias ultimately did show increased prejudice. But ironic processes should depend on control-related effort. Taking 1/f noise as a proxy for effort, results show that the effect of the feedback was moderated by 1/f noise. Participants demonstrating a low-effort 1/f pattern were unaffected by the manipulation (η_p² < .01), whereas those demonstrating a high-effort 1/f pattern showed larger effects (η_p² = .19). Results thus suggest that 1/f noise can provide novel explanatory power regarding behavior.     

Racial exclusion causes acute cortisol release among emerging-adult African Americans: The role of reduced perceived control

ABSTRACT

Racial discrimination contributes to stress-related health disparities among African Americans, but less is known about the acute effects of racial exclusion on the hypo-pituitary-adrenocortical response and psychological mediators. Participants were 276 Black/African American emerging-adults (54% female; M _age = 21.74, SD = 2.21) who were randomly assigned to be excluded or included by White peers via the game Cyberball. Racial exclusion (vs. inclusion) predicted: greater negative affect (F(1, 276) = 104.885, p < .0001), lower perceived control (F(1, 276) = 205.523, p < .0001), and greater cortisol release (F(1, 274) = 4.575, p = .033). Racial exclusion’s impact on cortisol release was mediated by lower perceived control (95% CI: .027, .112), but not negative affect (?.041, .013). These findings suggest that racial exclusion contributes to acute cortisol release, and that reduced perceived control is a consequence of racial discrimination that has important implications for the health of those who experience discrimination.     

Cyclists as a minority group?

In the social sciences, several definitions of minority group can be found. The definitions include different aspects such as power/status, number, distinctiveness, social category, group context, dispositions, and discrimination. Compared to motorized road users, cyclists are considered vulnerable road users because they lack physical protection. We argue that such definition does not capture the social and cultural aspects that characterize the membership within the group of cyclists. We offer arguments and reflections based on recent literature advocating that cyclists may share some features of the experience of minority groups. Although cyclists differ from other minorities in important respects, they manifest many of the characteristics by which minority groups are defined.